---
id: CVE-2025-40315
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  usb: gadget: f_fs: Fix epfile null pointer access after ep enable.

  A race condition occurs when ffs_func_eps_enable() runs concurrently
  with ffs_data_reset()
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  usb: gadget: f_fs: Fix epfile null pointer access after ep enable.

  A race condition occurs when ffs_func_eps_enable() runs concurrently
  with ffs_data_reset(). The ffs_…
severity: none
published: '2025-12-08'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T22:10:00.210'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-40315'
references:
  - url: 'https://git.kernel.org/stable/c/1c0dbd240be3f87cac321b14e17979b7e9cb6a8f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/30880e9df27332403dd638a82c27921134b3630b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9ec40fba7357df2d36f4c2e2f3b9b1a4fba0a272'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b00d2572c16e8e59e979960d3383c2ae9cebd195'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c53e90563bc148e4e0ad09fe130ba2246d426ea6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/cfd6f1a7b42f62523c96d9703ef32b0dbc495ba4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d62b808d5c68a931ad0849a00a5e3be3dd7e0019'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/fc1141a530dfc91f0ee19b7f422a2d24829584bc'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00201
epssPercentile: 0.09332
ingestedAt: '2026-10-14T23:00:02.022Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

usb: gadget: f_fs: Fix epfile null pointer access after ep enable.

A race condition occurs when ffs_func_eps_enable() runs concurrently
with ffs_data_reset(). The ffs_data_clear() called in ffs_data_reset()
sets ffs->epfiles to NULL before resetting ffs->eps_count to 0, leading
to a NULL pointer dereference when accessing epfile->ep in
ffs_func_eps_enable() after successful usb_ep_enable().

The ffs->epfiles pointer is set to NULL in both ffs_data_clear() and
ffs_data_close() functions, and its modification is protected by the
spinlock ffs->eps_lock. And the whole ffs_func_eps_enable() function
is also protected by ffs->eps_lock.

Thus, add NULL pointer handling for ffs->epfiles in the
ffs_func_eps_enable() function to fix issues

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.